The present invention relates to large scale X-Y plotting tables for handling elongated pliable sheet material that exceeds lengthwise the plotting range of the table.
While the present invention is not limited thereto, it is particularly suited to pattern layout in the manufacture of marine sails. Large sails for sailing craft are fabricated by assembling a plurality of smaller panels. Such panels usually are of triangular configuration and of various sizes. The sail maker works with bolts of fabric, and a single panel may have a length of many yards. Therefore, there has been a need for a plotting device able to handle large rolls of cloth and apply pattern outlines thereto extending over a substantial continuous distance. Heretofore, no efficient mechanism has been available for accomplishing such large scale pattern layouts. Consequently, an object of the present invention is to satisfy such need.
In general, prior attempts at large tables, and even small plotting tables, have relied upon vacuum systems for securing the workpiece. The table tops are perforated or grooved to enable the development of negative pressure beneath the workpiece to cinch the latter to the former. While this method is acceptable with certain types of workpiece material and for certain purposes, it is disadvantageous when handling pliable material and the tool employed by the table mechanism is required to apply downward pressure during its traverse of the workpiece.
Therefore, another object of the present invention is to provide an arrangement for securing a workpiece to a plotting table or the like that does not require interruption of the continuity of the workpiece supporting surface of the table.